Two-station broaching machine



June .28, 1955 o. J. ABBOTT, JR 2,711,674

TWO-STATION BROACHING MACHINE Filed July 15, 1954 8 Sheets-Sheet lINVENTOR.

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TWO-STATION BROACHING MACHINE Filed July 15, 1954 8 Sheets-Sheet 5 IN VEN TOR. 71 17/935072? J3".

June 28, 1955 O. J. ABBOTT, JR

TWO-STATION BROACHING MACHINE 8 Sheets-Sheet 6 Filed July 15, 1954 June28, 1955 o. J. ABBOTT, JR

TWO-STATION BROACHING MACHINE 8 Sheets-Sheet 7 Filed July 15, l954 NQPINVENTOR- 017m? J 771%075 J77 June 28, 1955 o. J. ABBOTT, JR 2,711,674

TWO-STATION BROACHING MACHINE Filed July 15, 1954 8 Sheets-Sheet 8United States Patent r 1 2,711,674 TWO-STATION BROACHING MACHINE OlneyJ. Abbott, Jr., Detroit, Mich, assignor to Colonial Breach Company,Warren Township, Macomb County, MiclL, a corporation of DelawareApplication July 15, 1954, Serial No. 443,555 Claims. (Cl. 90-33) Thisinvention relates to breaching machines and more particularly to animproved two-station pull-down breaching machine.

In breaching operations it is quiteoften necessary to use an extremelylong broach or a plurality of shorter breaches in order to remove thenecessary amount of metal to complete the breaching operation. In manyinstances these breaches are relatively large in diameter and areextremely cumbersome to handle. Also, the use of extremely long broachesrequires breaching machines which are very large and expensive tomanufacture and presents breach maintenance and care problems.Furthermore, many factories or plants do not have sufiicient head spaceto permit the use of a breaching machine which accommodates an extremelylong breach in the order of perhaps eight or ten feet. In the past whenit has been desired to pass more than one breach through an opening witha pull-down breaching operation, it has been necessary to manuallychange the broaches after each cycle. This is a time consuming andexpensive operation and greatly reduces the production efficiency.

It is an object of this invention to provide a breaching machine whichaccommodates a plurality of breaches and which is constructed andarranged so that each of the broaches can perform its operation on aworkpiece without being removed from the machine and in a completelyautomatic manner so that the operator need not touch the machine exceptto remove the finished workpiece therefrom and load a new workpiece tobe breached therein.

It is a further object of this invention to provide a pull-downbreaching machine of the aforementioned type, in which at least a pairof breach-handling chucks adapted to carry broaches are reciprocablysupported on the machine and are adapted to be automatically moved intoalignment with a breach-pulling chuck disposed on the eppesite side of aworkpiece supporting fixture therefrom so that the single stationpulling chuck coacts with the plurality of breach-handling chucks forthe breaching of a single workpiece.

It is a still further object of this invention to provide a breachingmachine of the aforementioned type in which a workpiece supportingstructure is shuttled into and out of operative position in timedrelationship with the movement of the'breach-handling and pullingchucks.

It is a still further object of this invention to provide a breachingmachine of the aforementioned type, which is efiicient and rapid inoperation, durable in construction, completely automatic, easy to set upand adjust, relativel simple and inexpensive in construction.

These and other objects of this invention will become apparent from thefollowing detailed description, taken in conjunction with theaccompanying drawings, in which:

Figure 1 is a fragmentary perspective view of the breaching machine ofthis invention;

Fig. 2 is a front elevational view of the structure illustrated inFigure 1;

Fig. 3 is a view partially in section and partially in elevation, of thestructure illustrated in Fig. 2, taken along the line 22 thereof;

Fig. 4 is a side elevational view of the structure illustrated in Figurel;

Fig. 5 is a sectional view of the structure illustrated in Fig. 3, takenalong the line 55 thereof;

Fig. 6 is a diagrammatic view of the hydraulic circuit of the machine ofthis invention; and

2,711,674 Patented June 28, 1955 Figs. 7a and 7b, when placed together,are a diagrammatic view of the electrical circuit of the machine of thisinvention.

Referring now to the drawing, it will be seen that the breaching machineincludes stationary supporting structure 9, in cluding a base portion 11and a vertical column 13. -A horizontal platform member 15 is supportedon the structure 9 and projects outwardly therefrom. The platform 15 hasways 17 adjacent the opposite sides edges thereof and a fixture 19 isslidably supported on the platform 15 and guided for movement inwardlyand outwardly relative to the vertical column by the ways 17. Thefixture 19 supports a workpiece 20 having an opening therein to bebreached. A pair of hydraulic piston and cylinder units 21 and 23 aresupported on the platform 15 and, as can be best seen in Fig. 6, each ofthese units includes a cylinder 25 having a bore fitting piston 27therein, to which a piston rod 29 is connected. The piston rods 29 areconnected in any suitable manner to the fixture 19, so that actuation ofthe units will move the fixture inwardly or outwardly on the platform.

A breach-handling shuttle 31 is reciprocably supported on the verticalcolumn 13 for reciprocation laterally thereof. In this connection, theshuttle includes a rearwardly projecting slide portion 33, whichslidably engages a platelike bearing surface 35 on the front face of thevertical column. The bottom of the shuttle 31 is guided forreciprocating movement in a way 37 on the front of the vertical columnabove the platform 15. A pair of side-by-side breach-handling chuckslides 39 and 41 are reciprocably supported on the shuttle 31 forvertical movement toward and away from the platform 15. The slides 39and 41 are reciprocably supported in suitable ways 43 on the shuttle 31.Handling chuck brackets 45 and 47 are adjustably connected with theslides 39 and 41 respectively and each of the brackets 45 and 47supports a breach-handling chuck 49 and 51 respectively. Thebreach-handling chucks are of a suitable spring-loaded release typesuch-as illustrated in United States Patent No. 2,539,981, issued toBenedict Welte on January 30, 1951, entitled Broaching Machine. Each ofthe breachhandling chucks 49 and 51 is illustrated as supportingbroaches 53 and 55 respectively.

Piston and cylinder units 57 and 59, for independently actuating thechuck slides, are supported on the vertical column behind the slides 39and 41 respectively.

As can be best seen in Figs. 5 and 6, each of the piston and cylinderunits 57 and 59 includes a cylinder 61 having a bore fitting piston 63therein and a piston rod 65 is connected with piston 63 and extendsbeyond cylinder 61 with the free end thereof being connected at 67 tothe adjacent handling chuck slide 39 or 4'1. A fluid conduit 69communicates with the top of piston and cylinder unit 57 and a conduit71 communicates with the piston and cylinder unit on the lower side ofthe piston 63. Conduit 73 communicates with the upper end of piston andcylinder unit 59, while conduit '75 communicates with the lower end ofthe unit. The conduits are adapted to be connected with a suitablesource of fluid under pressure, as will be hereinafter described, sothat independent movement of the pistons 63 can be obtaineTso as to movethe adjacent handling chucks individually and independently relative toeach other. A pair of vertically extending rods 77 are supported on thevertical column by suitable bracket means 79, on opposite sides of eachbreach-handling chuck. Adjustably connected with each rod is a breachtrip or release member 81, which is adapted to engage the adjacentbreach-handling chuck at a predetermined point in its downward movementtoward the fixture to cause the chuck to release the breach that it iscarrying. Also supporting each pair of rods 77, below the releasemembers 81, is a bracket 82, which supports a breach guide 63 which isadapted to prevent swinging of the broach during the shuttlingoperation. As can be best seen in Fig. 3, the broach guide includeslaterally adjustable elements 85, which can be adjusted radially of thebroach to properly engage the periphery thereof and guide the same.

A broach-pulling chuck 87 is supported below the fixture 19 in anadapter 89, which in turn is connected with a bracket member 90. Bracket90 is keyed to a main ram 91, having a movable cylinder and a borefitting piston 97. The ram and bracket are slidably supported on themachine base for vertical movement toward and away from the fixture. Thebore fitting piston 97 within the cylinder 95 includes a hollowvertically extending tubular portion 99, which extends upwardly beyondthe upper end of thee ylinder and is connected to a fitting or housingmember 100, which in turn is suitably supported in the stationarystructure of the machine. The

' hollow tube portion 99 is provided with apertures 101 in theperipheral wall thereof just above the bore fitting portion of thepiston 97 so as to communicate the interior of the tube portion 99 withthe portion of the cylinder 95 above the piston. A tube 103 extendsthrough the tube member 99 and the piston 97, so that the lower endthereof communicates with the portion of cylinder 95 below the piston,while the upper end thereof is disposed in the housing member andcommunicates with conduit 105 thorugh a passage 107 in the member 100.The upper end of tubular member 99 is open and communicates with aconduit 109 through a passageway 111 in the member 100. When it isdesired to move the broach-pulling chuck downwardly fluid is directedthrough conduit 105, passage 107 and the tube 103 to the bottom of thecylinder 95 so that fluid pressure between the bottom of the piston 97and the bottom wall of the cylinder will force the cylinder downwardly.At the same time fluid in the upper portion of the cylinder will flowthrough the apertures 101 in the tubular member 99 up through thetubular member and through passage 111 in member 100 and out throughconduit 109. When it is desired to raise the cylinder 95 and thus thebroach-pulling chuck, fluid under pressure is admitted through conduit109 While the fluid flows from the ram through conduit 105 in just thereverse manner as previously described. The broach-pulling chuck 87 maybe of any suitable type and may be similar to the broach-handling chuck.Suitable means are pro vided for actuating the chuck to cause it torelease from the broach at a predetermined point in its upward stroke,in substantially the same manner as with the handling chucks.

in order to shift the broach-handling chuck shuttle 31 laterally of themachine base to position either handling chuck in vertical alignmentwith the pulling chuck, a piston and cylinde unit 121 is provided andinterconnected with the machine vertical column and the shuttle adjacentthe upper end of the latter. As can be best seen in Figs. 3 and 6, thepiston and cylinder unit 121 includes a fixed cylinder 123 which issuitably connected with the vertical column of the machine. A borefitting piston 125 is disposed within the cylinder 121 and carriespiston rods 127 and 129 which extend through opposite ends of thecylinder and are suitably connected to the shuttle. Stop or abutmentmembers 131 and 133 are carried by the piston rods 127 and 129respectively, and are engageable with the stationary machine supportingstructure to limit the lateral movement of the shuttle. The stop orabutment members 131 and 133 are adjustable so that when the shuttle isin either of its shifted positions, that is fully to the right or fullyto the left, the stops will engage a portion of the machine stationarysupporting structure and prevent the shuttle from moving beyond a pointof alignment with the broach-pulling chuck disposed on the opposite sideof the fixture. The piston and cylinder unit 121 is connected with asuitable t fluid power source, as will be hereinafter described, so asto shift the shuttle between its first and second positions to aligneither of the handling chucks with the pulling chuck.

Referring now to Fig. 6, which is a diagrammatic illustration of thehydraulic circuit of the machine, the various components are illustratedin the normal inoperative machine position preparatory to starting anautomatic cycle of operation. In this position both the handling chuckpistons 63 are in their uppermost position, the ram cylinder 95 is inits uppermost position, the fixture is in its out position, and theshuttle is shifted to the right so as to position the left hand handlingchuck in alignment with the broach-pulling chuck. The main hydraulicpump which is a variable delivery type pump, and the auxiliary hydraulicpump 152, along with other pumps such as the coolant motor, chipconveyor motor and the like, are energized to circulate fluid underpressure through the system and are connected to a suitable fluidreservoir or tank 153. At the outset, and as will hereinafter appear inconjunction with the description of the electrical circuit, solenoid S1of a solenoidoperated, pilot-controlled, four-way valve 154 is energizedso that fluid flowing from auxiliary pump 152 to the valve throughconduit 155 will flow under pressure through conduit 157 to actuatepistons 27 and move the fixture 19 inwardly and thus carry the workpieceto a breaching position. Fluid in the opposite end of the cylinders 25will flow through conduit 159 and valve 154 to tank 153 through conduit161. When the fixture is moved to its inner position limit switch LS2 isactuated and the limit switch LS2 likewise is actuated in the oppositedirection when the fixture moves to its fully out position. fter thefixture has moved to its innermost position solenoid S2 ofsolenoid-operated, pilot-controlled, four-Way valve 163 is energized sothat fluid flowing from auxiliary pump 152 through conduit 155 will flowthrough valve 163, through conduit 69, to the upper end of the cylinder61 of the piston and cylinder unit 57, so as to move the piston 63thereof downwardly. Fluid in the lower end of cylinder 61 will flowthrough conduit 71 back through a counterbalance valve 165, whose onlyfunction is to maintain piston 63 in its position when the machine isidling, through conduit 167, valve 163 and conduit 161 to tank. When thehandling chuck 49, connected with piston rod 65 of unit 57, movesdownwardly it carries the broach downwardly into engagement with thepulling chuck 87 and is released from engagement with the chuck. Whenthe piston rod 65 moves downwardly limit switches LS3 and LS5 aretipped. Thereafter solenoid S4 which is connected with the main pump150, is energized. The energization of solenoid S4 in turn operates acontrol pilot valve causing the pump to shift the main rotor in the pumpso that fluid will flow through conduit 105 and into the main ramcausing the same to move downwardly on the first broaching stroke andpull the broach through the workpiece. The main pump 150 is normally ina neutral position wherein it does not pump oil through either conduit105 or conduit 109. However, when a solenoid is energized, the pilotcontrol valve in the pump shifts the rotor to cause fluid to flowthrough one conduit and permit fluid to return to tank through the otherconduit. Thus, when the cylinder moves downwardly fluid flows throughconduit 109 back to the pump. When the ram begins its downward movementlimit switch LS8 is tripped and When the ram reaches its lowermostposition it actuates limit switch LS7.

it should at this time be pointed out that the machine is provided witha prefill valve 167 which is connected with auxiliary pump 152 throughconduit 169 and which has conduits 1'70 and 171 leading therefrom whichare interconnected with conduits 109 and 10.5 respectively. Likewise acounterbalance valve 173 is provided in conduit, 109 to maintain the ramin position when the machine is idle. However, to more positively assurethe ram being in its uppermost position the prefill valve 167 isprovided and if when the machine is idle, the ram moves downwardly dueto leakage in the system or the like, so as to move out of engagementwith limit switch LS8, solenoid S11 is actuated and the ram will bemoved back to its raised position and held in such position. SolenoidS11, however, is inoperative during the normal cycling operation of themachine.

When the ram reaches its lowermost position solenoid S4 is de-energizedand ram movement is stopped, and solenoid S5 of four-way valve 154 isenergized so that fluid flows from the pump 152 through valve 154: andconduit 159 to move the fixture to its out position. At the end of thisstroke solenoid S5 is de-energized and solenoid S6 is energized, causingthe main pump 155 to deliver fluid under pressure through conduit 199and thus raise the ram to its raised position at which time switch LS7is actuated. The breach is thus moved back into engagement with thehandling chuck and is released by the pulling chuck. At the end of thisstroke solenoid S6 is de-energized and solenoid S7 of four-way valve 163is energized, causing fluid to flow under pressure from pump 152 throughconduit 155, conduit 170, counterbalance valve 165 and conduit 71, tocause the left hand handling cylinder to move to its uppermost positioncarrying the breach with it, which broach has been released by thebreach-pulling chuck, as previously described. When the handlingcylinder reaches its uppermost position switch LS3 is actuated.

At the end of the upward stroke or" the left hand handling cylinderpiston 63, solenoid S7 is de-energized, which stops the movement of thepiston, and solenoid S9 of the four-way valve 177 is energized so thatfluid will flow from pump 152, through conduit 155, fourway valve 177,conduit 1'79, into a flow-control valve 151 and from the valve 181through a conduit 183 to the right hand end of the cylinder 123, so asto move the piston 125 toward the left, which in turn will move theshuttle 31 to the left to bring the right hand handling chuck 51 intovertical alignment with the pulling chuck. it will be noted that thevalve 151 is of the cam operated type and has a plunger 185 projectingtherefrom, which is adapted to be actuated by a cam 187 illustrateddiagrammatically in Fig. 6 as being mounted on the piston rod 129,although actually the cam is mounted on the shuttle itself. As the cam187 engages the plunger 135, the flow of fluid through conduit 183 isdecreased and fluid entering the valve 181 through conduit 179 isreturned to tank through conduit Such an arrangement slows down themovement of the shuttle as it approaches its left hand position andprevents the shuttle stop 133 from engaging the machine stationarystructure with too much force. Fluid in the opposite end of the cylinder123 flows to tank through conduit 139, a flowcontrol valve 1% identicalwith flow-control valve 181, conduit 19]., four-way valve 177 andconduit 161. At the end of its stroke limit switch LS1 is actuated andsolenoid S9 is de-energized, while solenoid S1 of four- Way valve 154 isenergized. The energization of the solenoid 51 causes fluid to flow frompump 1152, through four-way valve 154, and conduit 157 into the fixturecylinders 21 and 23, so as to cause the pistons 27 thereof to moveinwardly and thus carry the fixture 19 inwardly to position theworkpiece in the proper position for the broaching operation, by thebroach carried in the right hand handling cylinder.

At the end of its inward movement limit switch LS2 is actuated andsolenoid S3 of four-way valve 192 is energized so that fluid flowingfrom pump 152 will flow through conduits 155 and 169 into valve 192 andfrom valve 192 fluid under pressure flows through conduit 193 into theupper end of piston and cylinder unit 59 to cause the piston thereof tomove downwardly and thus move the right hand broach-handling chuckdownwardly so as to move the lower end of the breach through theworkpiece and into engagement with the breach-pulling chuck. Downwardmovement trips-limit switches LS4 and LS6 and solenoid S3 isde-energized, while solenoid S4 is energized for starting the ram downon its second broaching stroke, in the same manner as previouslydescribed.

t the end of the downward movement of the ram solenoid S4 is deenergizedand solenoid S5 of the fourway valve 154 is energized for shuttling thefixture 19 to its out position, as previously described. When thefixture 19 is in its out position and has actuated limit switch LS2,solenoid S5 is de-energized and solenoid S6 energized so that fluidflowing from the main pump will move the ram back to its uppermostposition, as previously described.

At the beginning of this stroke limit switch LS7 is tripped and at theend of this stroke limit switch LS3 is actuated and solenoid S6 isde-energized, while solenoid S8 of four-way valve 192 is energized so asto shift four-way valve 192, thus causing fluid to flow from pump 152through conduits 155 and 169 into valve 192 and thence through conduit194, foot valve 195, which is identical with foot valve previouslydescribed, conduit 196, into the lower end of piston and cylinder unit59, so as to raise the right hand handling chuck and carry the broach toits uppermost position with the lower end thereof disposed above fixture19. When the right hand chuck reaches its uppermost position limitswitches LS4 and LS6 are actuated, solenoid S8 is de-energized andsolenoid Slti of four-way valve 177 is energized so that fluid flowingfrom pump 152 will flow through conduit 155, valve 177, conduit 191,flow control valve 199 and conduit 189, into the left hand end ofcylinder 123 so as to move the piston 125 to the right and return theshuttle 31 to its right hand starting position. It will be noted thatflow-control valve likewise has a plunger 197 engageable by a cam 198carried by the shuttle and actuatable as the shuttle approaches itsright hand position so as to by-pass fluid through a conduit 199 to tankand slow up the motion of the shuttle so that it will not strike thestop 131 with too much force. When the shuttle reaches its right handposition limit switch LS1 is again actuated and solenoid S10 istie-energized and the automatic cycle of the machine is completed. Itwill thus be appreciated that the entire cycle is automatic and ishydraulically and electrically controlled.

The specific electrical control circuit that operates to coordinate andcontrol the various components of the broaching machine is shown inFigures 7a and 7b; the two figures being joined together along the lineaa to provide a complete diagram. Certain minor electrical elements,unimportant to the invention or circuit, has e been deleted, such asoverload relays connected in the motor lines, fuses, light receptacles,and the like. It will also be apparent that in the description of theelectrical circuit energization of solenoids S1 to $10, which areelectrically interlocked with limit switches LS1 to L819, act to controlthe four-way valves of the hydraulic system and hence the various stepsin the cycling of the machine, as previously described. Inasmuch as thecircuit functions to permit not only automatic cycling of the machine,but also separate movement of the individual machine elements forsetting the machine up in operation, the explanation and description ofthe circuit diagram will be described in detail only for the automaticcycling operation of the machine.

It should be noted here that the illustrated circuit diagram depicts thecircuit conditions of the system before any power has been appliedthereto and when the broaching machine is in its initial startingcondition; that is, with the handling cylinders in their up position,fixture '19 in its out position, and handling shuttle 31 in its righthand position, and the main ram in its up position.

Power is supplied to the electrical control circuit across input linesL1, L2, and L3 from a suitable electrical power source; preferably athree-phase alternating current source. To permit isolation of thecircuit from the power source in the event that the circuit is to remaintie-energized for any length of time, a main disconnect switch 290 isinterposed in the lines. Connected across input lines L1, L2, and L3,through line switches 262, 204 and 2% respectively, are hydraulic motor159, auxiliary hydraulic motor 152, and the fluid coolant and chipconveyor motors 2&5 and 297; the latter of which are connected inparallel and to the input lines through switch 206. As will hereinafterbe described, actuation of switches 2&2, 204, and 2% to their closedpositions is controlled by a set of contactors 291, 2433, and 295,respectively, which are situated in the main control circuit such thatthe motors are energized only upon cyclic operation of the machine. Themain control circuit is energized through a pair of power lines 2553 and21$ and a step-down transformer 212, both of which are connected acrossinput lines L1 and L3. The output of transformer 212 is fed throughpower lines 214 and 216.

Situated in the circuit for the purpose of selecting either automatic orindividual component operation is a manually operated selector switchhaving a plurality of contacts A, B, C, N. Depending upon the opened orclosed condition of these switches, which is determined by the positionof selector arm 219, the machine will operate either automatically forperforming a complete broaching operation or in a manner whereby fixture19, left hand handling cylinder 57, right hand handling cylinder 59, ram91, or handling shuttle 31, will move, individually, in a forward andreverse direction. The latter arrangement is such that initial toolset-up of the machine is facilitated, but it is not thought necessaryherein to describe the electrical circuit and operation for each of suchindividual movements, so that only the automatic cycle will be describedin detail.

Assume that a workpiece 20 is positioned in fixture 19, a breach is heldby each of the handling chucks and the machine is otherwise in conditionfor a broaching operation. Then, selector arm 219 is turned to Autoposition to close switch contacts A and B. Initial initiation of the cicuit is controlled by start switch 220. De pressing the start buttonmomentarily closes switch 223 to energize contactors 291, 263 and 2&5through a circuit comprising line 214, the contactors, start switch 226,a stop switch 221 and line 216. Contactor 2S1 upon being energized willclose its associated line switches 202 for completing the power circuitto main hydraulic motor 15%; and further, close its associated switch2ll11 for providing a holding circuit therefor, around start switch224).

Similarly, contactors 203 and 265 will close their respecl tive lineswitches 264, 2% for starting auxiliary hydraulic motor 152, coolantmotor 265, and chip conveyor motor 297. Also, each of the contactors 233and 295 is provided with a holding switch 2l31, 2054, respectively,connected in parallel with start switch 220.

Closing of the start switch 229 further energizes control relays CR4,CR3 and CR9 and first pass pilot light 222 which is connected acrosscontrol relay CR4, the latter providing a visual indication that themachine is in preparation for undergoing a breaching operation with theleft hand positioned breach. The energizing circuit for control relayCR4 is from line 214, through relay CR4, limit switch LS1, which engagesits upper contact due to the handling shuttle being in its rightposition, line 223, through switches 2215 and 221 to line 216. Theenergizing circuit for control relay CR8 is from line 214 through relayCR3, limit switches LS9 and LS3, back to line 216; while theenergization circuit for relay CR9 is from line 214 through limitswitches. LSltl and LS4, and back to line 216. Limit switches LSE andL510 are associated with the handling shuttle 31 and act as interlocksfor opening these relay circuits in the event a broach fails to pick up.Limit switches LS3 and LS4 are closed due to the fact that the left handhandling chuck and right hand handling chuck are in their up positions,respectively.

4 As described thus far, each or" these elements is energized duringAuto cycle or the other specific operations of the machine with theexception, however, that the control arm 219 will be moved in differentpositions in accordance with the particular operation desired and hence,contacts AN of switch 219 will be changed accordingly.

The actual movement of the broaching machine is initiated by depressingthe Forward switch 224 which serves to energize control relays CR1 andCR1. Control relay CR6 closes its associated switch TtCRO for providinga holding circuit around switch 224 and is energized through a circuitincluding line 214, contact A of switch 218, through a pair of emergencystop switches 227, line 223, and back through switches 221i and 221 toline 216. Control relay CR1 is actuated through a circuit including line214, control relay CR1, normally closed switch .iCRS, normally closedswitch 1CR2, normally closed switch lCRiS, and switches 1CR9, 1CR8 toline 223 and back to the source. Switches 1CR9 and 1CR8 are normallyopen but due to relays CR8 and CR9 being energized, these associatedswitches are closed. Upon energization of control relay CR1, solenoid S1is energized through normally closed switches 1CR13 and 1CR7 and throughswitches 1CR4 and llCRl which are closed upon energization of relays CR1and CR4. As such, fixture 19 is driven to its in position by pistons andcylinder units 21 and 23, for placing the workpiece in broachingposition. This shuttle movement of the fixture trips limit switch LS2 toits up position for energizing control relay CR6 through a circuitextending between lines 214 and 223.

Control relay CR6 is inter-related with the solenoid S2 by an associatedswitch 1CR6 such that energization of control relay thus serves toenergize solenoid S2 through normally closed switch lCRld. and switches1CR6, ZCPA, and ZCRl, the latter being closed by the energization oftheir respective relays. Upon solenoid S2 becoming energized fluid flowsto the left hand handling cylinder for driving the handling chuck 49downward carrying the breach 53. In so doing, limit switches LS3 and LS5are tripped for de-energizing control relay CR8 and energizing controlrelay CR1 3. This action will then energize control relay CRltl, whichin turn will open normally closed contact iCRld in the circuit ofsolenoid S2 for de-energizing the circuit and stopping the downward motion of the handling cylinder. Meanwhile CRll will be energized b" theclosing of its switch 'ZCRlll. The energizing of control relay CRlllwill complete a circuit through solenoid 84 from line 208, throughswitches iCRll to line 21% back to its source such that fiuid flow iscontrolled to the ram 91 for drawing the ram downwardly on a breachingstroke. It will be noted that solenoid S4 is controlled through thecircuit comprising lines 203 and 2th which are connected directly to theinput lines L1 and L2. As the ram begins its downward movement, limitswitch LS3 is tripped for energizing relay CRiS for reasons which willhereinafter become apparent.

Upon reaching the bottom of its stroke, ram 91 trips limit switch LS7which energizes control relay CR13, for

opening switch 3CR13 in the circuit of control relay C1211. Thede-energization of control relay CRll opens switches 1CR11 and ZCRTT. inthe power circuit of solenoid S4 such that the fluid flow to the ramcylinder is stopped and hence, the ram is stopped. Control relay CR13upon de-energization also de-energizes switch lCRlS in the controlcircuit of solenoid S1 for de-energizing this solenoid; and closes itsassociated normally open switch SCRis for energizing solenoid S5 throughswitches 3CR6 and 3CRtl. Solenoid S5 in turn controls the flow of fluidto the fixture shuttle cylinders 25 to cause the fixture to shuttle toits out position, which action in turn trips limit switch LS2 in closingrelation with control relay CR7.

Tripping of limit switch LS2 de-energizes control relay 9: CR6 andfurther, de-energizes solenoid S due to the opening of switch 3CR6associated with the control relay CR6. This action operates to stop thefixture movement when it reaches its out position and further, serves toenergize control relays CR7 and CR12; the latter being energized due tothe closing of switch 3CR7 in its circuit, switches 2CR15 and 2CROhaving been previously closed. As a result of energization of relayCR12, solenoid S6 is energized through the line 20%, switches 1CR12 and2CR12 associated with control relay CR12 and line 210. Solenoid S6controls the flow of fluid to the main ram cylinder for forcing the ramupwardly on a return stroke. The upward movement of ram 91 trips limitswitch LS7 for de-energizing control relay CR13. Upon reaching the topof its stroke the ram trips limit switch LS which de-energizes controlrelays CR15 and CR12 due to the opening of switch 2CR15. Solenoid S6 isalso de-energized due to the opening of switches 1CR12 and 2CR12associated with the control relay CR12. Meanwhile control relay CR14 isenergized through limit switch LS7, normally closed switch 3CR15, andswitches 4CR7,

5CRO which are closed due to their associated relays being energized.Moreover, as relay CR15 is de-energized its normally closed switch 4CR15becomes closed for energizing solenoid S7 which functions to direct thefluid flow to the left hand handling cylinder for driving the handlingcylinder upwardly.

Upon moving upwardly, the left hand handling piston trips limit switchLS5 for de-energizing control relay CR10 and on further movementupwardly, trips limit switch LS3 for energizing control relay CR8. As aresult, switch 4CR8 opens the power to solenoid S7, tie-energizing thesame and stopping the fluid to the handling cylinder whereby the lefthand handling cylinder is stopped. Upon energizing control relay CR8,its associated switch 5CR8, in the control circuit of solenoid S9, actsto close the power line through the solenoid S9 such that the line iscompleted from line 214, solenoid S9, closed switches 1CR14, 4CR9,switch 5CR3, switch 3CR5 and relay switch 4CR1 to line 216. Thissolenoid controls valve 177 for directing the fiuid flow to the handlingshuttle 31 such that the handling shuttle moves toward the left forbringing the right hand positioned broach into cutting position. Uponbeginning its motion the handling shuttle triggers limit switch LS1 fordeenergizing control relay CR4 and energizing lock control relay CR2through switch 4CR4. The latter serves to prepare the apparatus for asecond pass operation wherein the right hand broach operates toadditionally broach the workpiece.

Upon completing its motion, the handling shuttle 31 triggers limitswitch LS1 to a closed position for energizing control relay CR5 and thesecond pass pilot light connected thereacross. Also, solenoid S9 isdeenergized due to switch 3CR5 being opened. Opening of the solenoid S9circuit serves to stop the shuttle movement. Energization of controlrelay CR5 also de-energizes the power circuit of control relay CR1 byopening its normally closed switch 1CR5. In turn, de-energization ofcontrol relay CR1 will serve to de-energize control relay CR7 by openingswitch 3CR1 whereby control relay CR3 is energized by the closing ofnormally closed switch 6CR7 and control relay CR14 is de-energized dueto the opening of its normally opened switch 4CR7. As such, the entirecircuit is reset for the second pass whereby the right hand broach willbe driven to perform its cutting operation.

In view of the fact that a considerable portion of the circuit isemployed during the second pass operation, this operation will bedescribed orilybriefly. The energization of relay CR3 and CR5 energizessolenoid S1, shuttling the fixture 19 in and thus tripping limit switchLS2 and energizing relay CR6. This action causes solenoid S3 to beenergized, thus moving the right hand handling cylinder 59 downwardly,tripping limit switch LS4 and de-energizing relay CR9 at the top of thestroke, whereas limit switch LS6 is closed when the cylinder reaches thebottom of its stroke. This causes energization of relay CR10, CR11 andsolenoid S4, as well as the de-energization of solenoid S3, thusstopping the downward movement of the handling cylinder and starting ram91 down on the breaching stroke. Movement of the ram causes limit switchLS8 to be tripped and relay CRIS to be energized near the top of the ram10 stroke, while limit switch LS7 is tripped and relay CRIS energized atthe bottom of the stroke. Relay CR13 will tie-energize relay CR11,solenoid S4, stopping the ram movement, and also energizing solenoid S5,causing the fixture to shuttle to its out position. The movement 15 ofthe fixture 19 to its out position trips limit switch LS2, thusde-energizing relay CR6 and solenoid S5, so as to stop further fixturemovement, while at the same time energizing relay CR7 and CR12 as wellas solenoid S6, thus causing the ram to move upwardly. As the ram 20starts its upward movement, relay CR13 is de-energized by the trippingof limit switch LS7 and when the ram reaches its upper position limitswitch LS8 is tripped, thus de-energizing the relay CRIS, CR12 andsolenoid S6, so as to stop the ram movement. Relay CR14 and solenoid S8thus energize sending the right hand handling cylinder upwardly trippinglimit switch LS6 and de-energizing relay CR10. When the handlingcylinder reaches its uppermost position limit switch LS4 is tripped,energizing relays CR9 and solenoid S10, while de-ener- 3 gizing solenoidS3 and thereby stopping the handling cylinder movement. Thereaftersolenoid S10 will cause the handling shuttle 31 to move to the right,tripping limit switch LS1 and de-energizing relay CR5 and the secondpass pilot light, while energizing relay CR4 and the 35 first pass pilotlight. Relay CR4 in turn de-energizes lock relays CR2, CR3, CR7, CR14and solenoid S10, thus stopping the handling shuttle movement and endingthe automatic cycle. If the workpiece 20 is unloaded from the fixture 19and a new workpiece loaded thereon,

the cycle will be repated by the operator merely pressing the forwardbutton.

It will thus be seen that the workpiece is automatically broached in arelatively simple and efiicient manner.

What is claimed is:

l. A broaching machine including stationary supporting structure, aworkpiece supporting fixture supported on said structure forreciprocating in and out movement, means for reciprocating said fixture,a carriage supported on said structure on one side of said fixture forreciprocating movement transversely of said structure, means forreciprocating said carriage, at least two broach-handling chuck meanssupported on said carriage for reciprocating movement toward and awayfrom said fixture, means for individually reciprocating saidbroach-handling chuck means, a single broach-pulling chuck meanssupported on said structure on the opposite side of said fixture forreciprocation toward and away from said fixture, means for reciprocatingsaid broach-pulling chuck means, said broach-pulling chuck means beingdisposed in alignment with one of said handling chuck means when saidcarriage is in one position and in alignment with another of saidhandling chuck means when said carriage is in another position so as tocoact with said handling chuck means to pull broaches through aworkpiece supported on said fixture and return the broaches to theirinitial position after the breaching operation.

2. A broaching machine including stationary supporting structure, aworkpiece supporting fixture supported on said structure forreciprocating movement, means for v reciprocating said fixture, acarriage supported on said structure on one side of said fixture forreciprocating movement transversely of said structure, means forreciprocating said carriage between a first position and a secondposition wherein said carriage is disposed transversely of its firstposition, a pair of side-by-side broachhandling chucks supported on saidcarriage for reciprocating movement toward and away from said fixture,means for individually reciprocating said broach-handling chuck means, abroach-pulling chuck supported on said structure on the opposite side ofsaid fixture for reciprocation toward and away from said fixture, meansfor reciprocating said broach-pulling chuck, said broachpulling chuckbeing disposed in alignment with one of said handling chucks when saidcarriage is in said first position and with the other of said handlingchucks when said carriage is in said second position, so that saidpulling chuck can coact with each of said handling chucks to pullbroaches through a workpiece supported on said fixture and return thesame to their initial position after the breaching operation.

3. A broaching machine including stationary supporting structure, aworkpiece supporting fixture supported on said structure for movementrelative thereto, means for moving said fixture, a carriage supported onsaid structure on one side of said fixture for reciprocating movementtransversely of said structure and generally parallel to said fixture,means for reciprocating said carriage, a pair of side-by-sidebroach-handling chucks supported on said carriage for reciprocatingmovement toward and away from said fixture, means for individuallyreciprocating said handling chucks, a broach-pulling chuck supported onsaid structure on the opposite side of said fixture for reciprocationtoward and away from said fixture, means for reciprocating said pullingchuck, said broachpulling chuck being disposed in alignment with one ofsaid handling chucks when said carriage is in one position and with theother of said handling chucks when said carriage is in another position,each of said handling chucks being adapted to carry a broach and movethe same partially through a workpiece and into engagement with thepulling chuck which will pull the broach through the workpiece, meansfor actuating said broach-handling chuck reciprocating means to causeone of said handling chucks to move toward said fixture so that a broachcarried thereby will be engaged by said broach-pulling chuck, means foractuating said broach-pulling chuck reciprocating means to cause saidpulling chuck to move away from said fixture so as to pull said broachthrough the workpiece, means actuatable to release said firstbroach-handling chuck from a broach after it has moved a predetermineddistance toward said fixture so that said broachpulling chuck can pullthe broach completely through the workpiece and fixture, means foractuating said fixture, moving means to cause said fixture to move outof alignment with said broach-pulling chuck so that said broach-pullingchuck can move the broach upwardly without interference from the fixtureor workpiece carried thereby, means for actuating said broach-pullingchuck reciprocating means to cause said chuck to move toward saidfixture so as to move the broach into engagement with said first broachhandling chuck, means for actuating said broach-handling chuckreciprocating means to cause said chuck to move away from said fixtureso as to move said broach to the opposite side of said fixture, meansactuatable to release said broach-pulling chuck from a broach after ithas moved a predetermined distance toward said fixture to permit saidhandling chuck to move the broach beyond the fixture, means foractuating said fixture moving means to cause said fixture and aworkpiece carried thereby to move back to the initial position after thebroach has been moved to said opposite side, means for actuating saidcarriage reciprocating means to cause said carriage to move to aposition in which said second broach-handling chuck is disposed inalignment with said broach-pulling chuck, means for actuating saidbroach-handling chuck reciprocating means to cause said second handlingchuck to move toward said fixture so as to move a broach carried therebyat least partially beyond said fixture and into engagement with saidbroach-pulling chuck, means for actuating said broach reciprocatingmeans to cause said chuck to move away from said fixture, meansactuatable to release said second broach-handling chuck from its broachat a predetermined point of its movement toward said fixture so thatsaid broach-pulling chuck can pull the broach to the opposite side ofsaid fixture, means actuatable to thereafter actuate said fixturereciprocating means to cause said fixture to move out of alignment withsaid broachpulling chuck, means actuatable thereafter to cause saidbroach-pulling chuck reciprocating means to move said broach-pullingchuck toward said fixture to cause the broach to again engage saidsecond broach-handling chuck, means actuatable thereafter to cause saidhandling chuck reciprocating means to move said second broachhandlingchuck away from said fixture to return the broach carried thereby to aposition on the opposite side of said fixture, means actuatable torelease said broachpulling chuck from the broach so as to permit thebroach to be pulled to the opposite side of said fixture, meansactuatable thereafter to cause said fixture reciprocating means toreturn said fixture to its initial position, means actuatable thereafterto cause said carriage reciprocating means to move said carriage to itsinitial position, and means for synchronizing the operation of thevarious moving and reciprocating means to cause said machine to operateautomatically, whereby the workpiece may then be removed after havingbeen broached by two broaches.

4. A broaching machine including stationary supporting structure, aworkpiece supporting fixture supported on said structure forreciprocating in and out movement, means for reciprocating said fixture,a carriage supported on said structure on one side of said fixture forreciproeating movement transversely of said structure, means forreciprocating said carriage, at least two broach-handling chuck meanssupported on said carriage for reciprocating movement toward and awayfrom said fixture, means for individually reciprocating saidbroach-handling chuck means, a single broach-pulling chuck meanssupported on said structure on the opposite side of said fixture forreciprocation toward and away from said fixture, means for reciprocatingsaid broach-pulling chuck means, said broach-pulling chuck means beingdisposed in alignment with one of said handling chuck means when saidcarriage is in one position and in alignment with another of saidhandling chuck means when said carriage is in another position so as tocoact with said handling chuck means to pull broaches through aworkpiece supported on said fixture, and means for synchronizing theoperation of said reciprocating and moving means to cause said machineto operate automatically in a predetermined cycle.

5. A broaching machine including stationary supporting structure, aworkpiece supporting fixture supported on said stationary structure formovement relative thereto, means for moving said fixture relative tosaid structure, carriage means supported on said structure on one sideof said fixture for movement relative to said structure, means formoving said carriage means, at least two broach-handling chuck meanssupported on said carriage means for reciprocating movement toward andaway from said fixture, means for individually reciprocating saidbroach-handling chuck means, a single broach-pulling chuck meanssupported on said structure on the opposite side of said fixture forreciprocation toward and away from said fixture, means for reciprocatingsaid broachpulling chuck means, said broach-pulling chuck means beingdisposed in alignment with one of said handling chuck means when saidcarriage is in one position and in alignment with another of saidhandling chuck means when said carriage is in another position, so as tocoact with said handling chuck means to pull broaches through aworkpiece supported on said fixture and return the broaches to theirinitial position after the breaching operation.

No references cited.

